Just This One Night
by TheRedTears
Summary: Placed in the City of Glass at the scene towards the end of chapter 14. Jace climbs up to Clary's room at Amatis's house and declares his love for her. One thing leads to another.
1. Chapter 1

**This story is placed towards the end of Chapter 14 in City of Glass. Clary is in her room at Amatis's house in Alicante, and it's the night before Valentine returns with his proposal for the city. Jace climbs up to Clary's room, and declares his love for her. One thing leads to another.**

"There is no pretending," Jace said with absolute clarity. "I love you, and I will love you until I die, and if there's a life after that, I'll love you then."

She caught her breath. He had said it – the words there was no going back from. She struggled for a reply, but none came.

"And I know you think I just want to be with you to – to show myself what a monster I am," he said. "And maybe I am a monster. I don't know that answer to that. But what I do know is that even if there's demon blood inside me, there is human blood inside me as well. And I couldn't love you like I do if I wasn't at least a little bit human. Because demons_ want_. But they don't love. And I – "

He stood up then, with a sort of violent suddenness, and crossed the room to the window. He looked lost.

"Jace?" Clary said, alarmed. "What's wrong?"

"I shouldn't have told you like that," he said, not looking at her. "I'm sorry, that was probably a lot to take in. You looked so… shocked." The tension underlying his voice was a live wire.

"I was," she said. "I've spent the past few days wondering if you hated me. And then I saw you tonight and I was pretty sure you did."

"Hated you?" he echoed, looking bewildered. He reached out then and touched her face, lightly, just the tips of his fingers against her skin. "I told you I couldn't sleep. Tomorrow by midnight we'll either be at war or under Valentine's rule. This could be the last night of our lives, certainly the last even barely ordinary one. The last night we go to sleep and get up just as we always have. All I could think was that I wanted to spend it with you."

Her heart skipped a beat. "Jace – "

"I don't mean it like that," he said. "I won't touch you, not if you don't want me to. I know it's wrong – God, it's all kinds of wrong – but I just want to lie down with you and wake up with you, just once, just once ever in my life." There was desperation in his voice. "It's just this one night. In the grand scheme of things, how much can one night matter?"

_Because think how we'll feel in the morning. Think how much worse it will be pretending that we don't mean anything to each other in front of everyone else after we've spent the night together, even if all we do is sleep. It's like having just a little bit of a drug – it only makes you want more._

But she would want more no matter what, she realized. She wanted to do more than just sleep. There was nothing she had ever wanted in her life more than this night with Jace.

"Close the curtains, then, before you come to bed," she said. "I can't sleep with this much light in the room."

The look that washed over his face was pure incredulity. He really hadn't expected her to say yes, Calry realized in surprise, and a moment later he had caught her and hugged her to him, his face buried in her still-messy-from-sleep-hair. "Clary…"

"Come to bed," she said softly. "It's late." She drew away from him and drew the covers up to her waist. Somehow, looking at him like this, she could almost imagine that things were different, that it was many years from now and they'd been together so long that they'd done this a hundred times, that every night belonged to them, not just this one. She watched him as he reached to jerk the curtains shut and then unzipped his white jacket and hung it over the back of a chair. He was wearing a pale gray T-shirt underneath, and the Marks that twined his bare arms shone darkly as he unbuckled his weapons belt and laid it on the floor. Clary could see the outlines of his lean muscles under the thin shirt. He unlaced his boots and stepped out of them as he came towards the bed, and he stretched out very carefully beside Clary. Lying on his back, he turned his head to look at her.

"Good night, Clary," he said.

His hands lay flat on either side of him, his arms at his sides. He seemed to be barely breathing; she wasn't sure she was breathing herself. She slid her own hand across the bed and laced her fingers with his. "I don't want to sleep just yet," she whispered softly.

His face was unreadable. "What do you want to do then ?"

"I want to – " she hesitated. "I want to talk."

"About what?" He had opened his eyes now, and they were gazing at her.

"I don't know… you think of something first." She hadn't really thought about what they would talk about, she just didn't want to simply lie there in silence as they waited to fall asleep.

"Did you really kiss Sebastian?" Jace asked in a firm tone. There was a hard look on his face.

Clary was caught by total surprise. Her eyes widened, and then she looked down to avoid meeting his eyes. "Yes… but I didn't want to – I mean, I wasn't – I just – " she stammered helplessly.

"Was he good?" Jace interrupted her stuttering. The expression on his face hadn't changed. "Was he better than me?"

Clary was surprised yet again. "I –" she started, but didn't get to finish.

Jace rolled over on the bed and ended up on top of her, his knees on either side of her waist, and his hands pressing down on the mattress by both sides of her head. His face hovered above hers, and he leaned down – very, very slowly – and gently pressed his lips against hers. There wasn't much pressure, but the kiss lasted a while.

"Better than that?" Jace asked again. His tried to keep his expression the same, but Clary could practically hear his heart beating out of his chest, and they were both a little out of breath.

Clary was speechless. She quickly shook her head no. Then, without even realizing what she was doing, he reached out both of her arms and placed them on Jace's back, bringing him down towards her until he was lying on top of her. His breath was hot against her ear. She turned so that she was facing him. This time, she was the one who kissed him. She felt him tense and then relax. Taking this as a sign, she deepened the kiss, and she felt a sudden lust stir inside her. She knew it was wrong, that all this was wrong, but at that moment, she wasn't even thinking about it.

Jace ran his hands through her long red curls, and slipped his other hand down her side so that it rested at her waist. Clary felt shivers up her spine, her body reacting to Jace's touch. The kiss grew hungrier, and Clary opened her mouth to let out a small moan. Jace took this opportunity to let his tongue slip inside her mouth, and Clary gasped in surprise. They explored each other's mouths, and their tongues danced together.

It seemed like it had been forever when the kiss broke off, and they were both breathing heavily. Jace leaned in again, and this time, he planted small kisses along her jawbone all the way up to her ear. A sound escaped from Clary's lips, and he quickly caught her lips in a chaste kiss, trapping the sound. She ran her hands through his golden locks while he explored her body. His hands traveled lower until they reached the bottom of her thin camisole, where they started to move up again, under the cami.

"Jace…" Clary whispered.

Jace immediately pulled away. Clary could see from his face that he was just as nervous as she was. His cheeks burned a bright pink, and she was sure hers were the same. "Do you want me to stop?" He asked softly, but Clary couldn't help but notice that his face fell.

In reply, Clary took his hands, and guided them back to under her shirt. She sat up a little, and with her hands still on his, she helped him to take off her cami. It was then that she suddenly felt very exposed, and tried her best to cover herself with her arms.

"Don't," Jace said, staring at her. He slowly grasped her forearms and moved them out of the way. "You're beautiful."

Clary was shocked, flushed a deep shade of red, and looked down in embarrassment. When she looked back up, she found that Jace had busied himself with the task of removing his own shirt, and when he did, she was mesmerized. She traced her fingertips lightly against the dozens of small white scars that covered his chest. She bent to gently kiss every one of them, then looked up at Jace's face.

Jace gave her a crooked smile. "So now that we're both half naked, what do you want to do?"


	2. Chapter 2

Without giving her time to respond, he flipped her over so that she was lying on her back, and when her head hit the soft pillows, she gave a small squeak. His gaze came down to her breasts, and he tentatively massaged one of them, tilting his head to look at her reaction. She closed her eyes and exhaled deeply, and then nodded slightly to give him approval. She arched her back slightly to give him easier access, and he moved both his hands behind her back to unhook her bra. Very slowly, he took off the straps from her shoulders, and then tossed the laced white bra to a corner of the room. Clary squeezed her eyes shut and her breath hitched.

Jace used both of his hands to feel her breasts. They were a good size, he decided, not huge, but not tiny either. He traced kisses down her neck, lingered at her collarbone, and then finally moved down and took her fleshy pink nipple in his mouth. Clary squirmed in delight and moaned. He let his tongue flick at the bud, and bit down gently with his teeth. He could feel the nub hardening in his mouth, and then he realized that he was hardening as well. He tried to calm himself, but he heard Clary let out a small gasp. She had felt his erect manhood press against her inner thigh.

"Is that…" Clary asked timidly, the thought that she was still a virgin suddenly springing into her head.

Jace looked embarrassed and a bit apologetic. "I'm sorry… we don't have to do anything you don't want to, Clary."

Clary swallowed the lump in her throat. "No, it's okay." She took another deep breath. "I'm ready. I decided a long time ago that if I was going to do it with anyone, it would be you."

Jace was startled by her words. "But we're – ''

"Shhh… I don't care." Clary didn't want this moment to be ruined by the inevitable thought that they were related; she just wanted to be with Jace, to do this with him.

Jace lowered his mouth again and trailed butterfly kisses along her breasts. Then he pressed his mouth in the valley between them, while his hands played and pinched the nipples. He let his tongue slide out of his mouth, and licked across her flat stomach until he reached her belly button, where his tongue traced the rim. Clary squirmed underneath him with pleasure and moaned his name. Jace melted at the sound of her saying his name so intimately. He continued down to the band of her pajama pants. His body was between her legs, with his head just above her most private area.

"It's okay," she whispered. He could hear the shakiness in her voice.

"I'll be gentle," he said softly.

With that, he started on removing her pants. He tugged them down carefully, letting his fingers linger on her hips. She giggled nervously, and he could feel the vibrations underneath him as she did so. Once the pajamas were gone, all that was left on her body was her light blue underwear. He couldn't see much in the dark, but he could smell the faint sweet scent of her arousal, and his manhood pulsed with impatience. He couldn't control himself as he practically tore her underwear off, revealing a small patch of reddish brown hair, and the intoxicating scent of her wetness wafted into his nose.

Experimentally, he took one finger and ever so lightly, touched her folds. She buckled with pleasure, and let out a whine, begging him to go on. He stroked harder now, feeling the soft, fleshy folds of her vagina. Clary had never felt anything so good. She was caught in pure bliss and never wanted it to end. Carefully, he inserted one finger up into her. She gasped loudly, and writhed around, trying to get more friction. Sensing her need, he inserted another finger, and began to move them in and out. The moisture collected on his fingers, and he placed them into his mouth, tasting her delicious juices. Jace bent in, and let his tongue slip out of his mouth and lick her, sending a shockwave all throughout Clary's body. He pursed his lips around her sucked on her swollen clitoris. He explored all around her opening with his mouth, and thrusted his tongue in and out of her. He brought up two of his fingers again, and inserted them, the second finger stretching her wet inside out in combination with the first while his mouth was busy tasting all around.

Jace sensed she was near. Abruptly, he stopped everything. Clary was on the edge and bucked her hips wildly towards him when he removed his fingers; she needed the friction for her release.

Jace shifted upwards and kissed her open mouthed, so that that she could taste herself. Now in position, he grinded his clothed manhood against her entrance. Her hands grasped onto his butt and pressed him harder against herself, she needed it so much she was about to lose her mind.

"Jace… don't make me wait any longer. Just do it, I need you," she managed to force out in between her sounds of satisfaction.

"Okay, okay. Hold on," he said, struggling to remove his pants, as well as his boxers. In her desperate need, Clary reached over and searched around on his abdomen for the top of his boxers, her hands coursing over his defined and well-toned muscles. She finally found it, and yanked down his boxers, revealing a fine trail of blond hair, and his manhood.

She couldn't really tell how large he was, but when she timidly felt for his penis, her breath drew in sharply at the size of it. She wasn't even sure it would fit.

Jace groaned at her touch. "Clary," he said with urgency, "please… touch me. Make me feel good."

Reluctantly at first, Clary moved her hand up and down his shaft, from the base to the tip. However, when he uttered her name a number of times, she began to stroke harder, determined to pleasure her as much as he had done for her. She could feel the warmth of it in her hand, and it pulsed and twitched as if it were alive.

"Ah… Clary… I can't wait any longer!" he finally exclaimed, and leaned down to position himself at her entrance. "Are you ready? This might hurt, but I promise I'll try my best to go slowly at first."

She nodded, and in a whisper that was barely audible, she said, "I'm ready Jace."

He brought his head down and sucked on the skin at the base of Clary's neck. While she was distracted, he glided into her with one swift movement, and broke the membrane inside.

Out of all the women he had been with, Jace had never felt anything as good as the heat and tightness of Clary. He had to do everything he could to stop himself from coming right there on the spot.

Clary whimpered in pain, and quickly brought a hand to her mouth to muffle her scream. Tears welled up in her eyes, and overflowed down her cheeks.

"I'm sorry it hurts," Jace said. He looked at her lovingly, and used his thumbs to lightly wipe the tears away. He kissed the hand that was covering her mouth, and then tenderly planted kisses all over her while he was still inside of her, letting her get used to his size.

After a few moments, Jace felt the inner muscles surrounding his shaft relax a bit, and Clary's eyes had dried up. Soundlessly, she gave him a reassuring nod, and he began to rock in and out of her.

At first the sensation was strange for Clary. She felt extremely full, like she was being filled up down there. But after a while the pumping began to feel good, and soon enough, she was falling in rhythm with Jace, their bodies pressed close together, the smells of sex drifting around them. Jace's back was sheer with a thin layer of sweat, and Clary found it difficult to grab onto him as he grinded into her. She let out countless moans, and bit her lip viciously as her sounds came. Her hands roamed all over his body, as did his with hers, and they kissed passionately over and over again.

All of a sudden, Jace groaned loudly, and yanked Clary into a different position. He was now on his back, with Clary riding on top of him. He began to thrust faster than ever before, and Clary felt herself nearing her climax.

"Clary… Ah… I'm so close…" Jace panted, putting all his energy into one final thrust. He pulled out completely, and then jammed his manhood back into Clary, and she screamed – whether in pleasure or pain, even she didn't know.

He released inside of her at the same time she came, their fluids mixing. They both went limp, and Clary fell on top of him. Jace felt all the muscles in his body go weak, and as he slowly pulled out of her, he rolled around and hugged Clary tightly to his chest. The bed sheets were damp with sweat and all sorts of other liquids, but Jace pulled up the covers around them anyway.

Exhausted, Clary tangled her legs with his, and draped her arms around him. Jace laid beside her slowly stroked her hair.

"Goodnight, Jace," Clary stifled a yawn. "I… I love you."

Jace was silent, but Clary didn't even notice as she fell fast asleep. He lay there for a while, treasuring the moment. A very little light filtered into the room past the edge of the curtains, just enough to show the outline of her face. Jace tried his best to memorize those features, the features of the girl he loved.

He knew he had to leave her. He pulled himself out of bed, tucking her covers back up against her neck, and dressed himself. He found a piece of paper and a pen, and began to write.

_Despite everything, I can't bear the thought of this ring being lost forever, any more than I can bear the thought of losing you forever. And though I have no choice about the one, at least I can choose about the other. _

He finished up the letter, and removed the Morgenstern ring that hung from a chain around his neck. He placed the ring on the nightstand beside the bed, and then the letter on top of it. He bent over and kissed Clary, his sister, on her forehead for what seemed like to him the last time. He loved her with all his heart, flesh and blood or not.

Filled with sorrow and determination, Jace walked out the door of Amatis's house, and headed for the Hall of Accords.

**Whoo! That was really long for my first Fanfiction. Hoped you liked it. Review please!**


End file.
